1. Field of the Invention
The invention relates generally to a parallel optical interconnection module for transmitting an optical signal over an optical fiber and receiving an optical signal from the optical fiber, and method of manufacturing the same. More particularly, the present invention relates to a parallel optical interconnect optical transmit/receive module comprising an optical waveguide having a lens type reflection surface for reducing the coupling loss generated due to alignment error when it is coupled with an optical fiber, a silicon optical bench for reducing the coupling loss generated due to alignment error when it is coupled with the optical fiber, and a ferrule by which fixture to the optical waveguide for optical interconnection is facilitated.
2. Description of the Prior Art
Generally, in a low-speed system, or the like, interconnection between a circuit substrate and a circuit substrate, and a chip and a chip or a system is made through an electrical metal cable. However, as information becomes large-scaled and the transfer speed becomes rapid in a next-generation information communication system consisting of a large-capacity parallel computer, an ATM switching system of over 1 Tb/s, and the like, electrical problems such as skew, EMI (electromagnetic interference), etc, are caused if this metal cable is employed. Due to this, the operation efficiency of the system is lowered and the integration of the system is made difficult.
Therefore, there has recently been developed a technology of optical interconnection using an optical transmit/receive module. An optical interconnecting method within the optical transmit/receive module includes: a method of directly interconnecting an optical receive device to a ribbon optical fiber multi-channel optical connector having a reflection mirror located at an angle of inclination of 45°, a method of interconnecting a polymer optical waveguide having a reflection mirror located at an angle of inclination of 45° to an optical transmit/receive device and interconnecting the polymer optical waveguide to the multi-channel optical connector, a method of vertically interconnecting the optical transmit/receive device to the polymer optical waveguide and interconnecting the polymer optical waveguide to the multi-channel optical connector, a method of vertically interconnecting the optical transmit/receive device fixed to a plastic package to the multi-channel optical connector, and the like. At this time, a vertical cavity surface emitting laser (VCSEL) array is usually used as the optical transmit device, which is the light source. In other words, the photodetector includes a photo diode (PD) array.
Korean Patent Application No. 2000-7003642 (filed on Apr. 4, 2000) entitled ‘Optical Module’ discloses an optical module in which light oscillated through an outgoing unit is reflected by the optical waveguide by 90° and the light is then transmitted to an optical fiber connected to an optical connector along a core formed at the substrate.
‘ParaBIT-1: 60-Gb/s-Throughput Parallel Optical Interconnect Module by N. Usui’ (May, 2000, ECTC 2000) discloses a module having a structure in which a 24-channel waveguide film with a plan reflection mirror is located by an angle of inclination of 45° and a 24-optical fiber BF connector are connected, and in which the waveguide film and the connector are manually assembled.
Of these prior arts, it is the method of interconnecting the optical transmit/receive device to the polymer optical waveguide having a reflection mirror located at an angle of inclination of 45° and interconnecting the polymer optical waveguide to the multi-channel optical connector, is the most effective method. The reason is that the reflection mirror can be easily formed and the function of the entire module can be extended since an optical coupler, WDM (wavelength division multiplexing) device, etc. can be built in the polymer optical waveguide.
However, a large coupling loss is generated even though a slight alignment error is caused when the optical transmit/receive device and the optical fiber are coupled if the above optical interconnection technology is employed in the future in order to manufacture a parallel optical interconnect optical transmit/receive module having an extended function. Therefore, there is a need for a parallel optical interconnect optical transmit/receive module capable of minimizing the coupling loss.